Re: Memory overcommit

[KAMEZAWA Hiroyuki]

On Mon, 26 Oct 2009 17:16:14 +0100
Vedran FuraÄ <vedran.furac@xxxxxxxxx> wrote:
> >  - Could you show me /var/log/dmesg and /var/log/messages at OOM ?
> 
> It was catastrophe. :) X crashed (or killed) with all the programs, but
> my little program was alive for 20 minutes (see timestamps). And for
> that time computer was completely unusable. Couldn't even get the
> console via ssh. Rally embarrassing for a modern OS to get destroyed by
> a 5 lines of C run as an ordinary user. Luckily screen was still alive,
> oomk usually kills it also. See for yourself:
> 
> dmesg: http://pastebin.com/f3f83738a
> messages: http://pastebin.com/f2091110a
> 
> (CCing to lklm again... I just want people to see the logs.)
> 
Thank you for reporting and your patience. It seems something strange
that your KDE programs are killed. I agree.

I attached a scirpt for checking oom_score of all exisiting process.
(oom_score is a value used for selecting "bad" processs.")
please run if you have time.

This is a result of my own desktop(on virtual machine.)
In this environ (Total memory is 1.6GBytes), mmap(1G) program is running.

%check_badness.pl | sort -n | tail
--
89924	3938	mixer_applet2
90210	3942	tomboy
94753	3936	clock-applet
101994	3919	pulseaudio
113525	4028	gnome-terminal
127340	1	init
128177	3871	nautilus
151003	11515	bash
256944	11653	mmap
425561	3829	gnome-session
--
Sigh, gnome-session has twice value of mmap(1G).
Of course, gnome-session only uses 6M bytes of anon.
I wonder this is because gnome-session has many children..but need to
dig more. Does anyone has idea ?
(CCed kosaki)

Thanks,
-Kame




#!/usr/bin/perl

open(LINE, "ps -A -o pid,comm | grep -v PID|") || die "can't ps";

while (<LINE>) {
	/^\s*([0-9]+)\s+(.*)$/;
	$PID=$1;
	$COMM=$2;
	open(SCORE, "/proc/$PID/oom_score") || next;
	$oom_score = <SCORE>;
	chomp($oom_score);
	close(SCORE);
	print $oom_score."\t".$PID . "\t",$COMM."\n";
}
close(LINE);